openwrt/target/linux/ipq806x/patches-5.15/113-v5.19-02-PM-devfreq-Fix-kernel-panic-with-cpu-based-scaling-t.patch

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From 57e00b40033a376de3f3cf0bb9bf7590d2dd679d Mon Sep 17 00:00:00 2001
From: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Date: Tue, 14 Jun 2022 13:06:59 +0200
Subject: [PATCH 1/1] PM / devfreq: Fix kernel panic with cpu based scaling to
passive gov
The cpufreq passive register notifier can PROBE_DEFER and the devfreq
struct is freed and then reallocaed on probe retry.
The current logic assume that the code can't PROBE_DEFER so the devfreq
struct in the this variable in devfreq_passive_data is assumed to be
(if already set) always correct.
This cause kernel panic as the code try to access the wrong address.
To correctly handle this, update the this variable in
devfreq_passive_data to the devfreq reallocated struct.
Fixes: a03dacb0316f ("PM / devfreq: Add cpu based scaling support to passive governor")
Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
---
drivers/devfreq/governor_passive.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c
index 72c67979ebe1..091a69e1f487 100644
--- a/drivers/devfreq/governor_passive.c
+++ b/drivers/devfreq/governor_passive.c
@@ -407,8 +407,7 @@ static int devfreq_passive_event_handler(struct devfreq *devfreq,
if (!p_data)
return -EINVAL;
- if (!p_data->this)
- p_data->this = devfreq;
+ p_data->this = devfreq;
switch (event) {
case DEVFREQ_GOV_START:
--
2.37.2